US20030023204A1 - Catheter having a funnel-shaped occlusion balloon of uniform thickness and methods of manufacture - Google Patents

Abstract

Methods and apparatus are provided for removing emboli during an angioplasty, stenting or surgical procedure comprising a catheter having a funnel-shaped occlusion balloon of uniform thickness disposed on a distal end of the catheter. The occlusion balloon is fused to the distal end so that it provides a substantially seamless flow transition into a working lumen of the catheter. Additionally, a distal edge of the occlusion balloon is configured to be in close proximity with an inner wall of a vessel to facilitate blood flow into the catheter and efficiently remove emboli.

Description

REFERENCE TO RELATED APPLICATIONS
• The present application is a continuation-in-part of U.S. patent application Ser. No. 09/418,727, filed Oct. 15, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 09/333,074, filed Jun. 14, 1999, now U.S. Pat. No. 6,206,868, which is a continuation-in-part of International Application PCT/US99/05469, filed Mar. 12, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 09/078,263, filed May 13, 1998.[0001]
FIELD OF THE INVENTION
• This invention relates to apparatus and methods for removing emboli during vascular interventions. More particularly, the apparatus and methods of the present invention provide a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and removes emboli from a treatment vessel via a funnel-shaped taper of the occlusion balloon.[0002]
BACKGROUND OF THE INVENTION
• Today there is a growing need to provide controlled access and vessel management during such procedures as stenting, atherectomy and angioplasty. Generally during these procedures there is a high opportunity for the release of embolic material. The emboli may travel downstream from the occlusion, lodging deep within the vascular bed and causing ischemia. The resulting ischemia may pose a serious threat to the health or life of a patient if the blockage forms in a critical area, such as the heart, lungs, or brain.[0003]
• Several previously known apparatus and methods attempt to remove emboli formed during endovascular procedures by aspirating the emboli out of the vessel of interest using a catheter having an occlusion balloon. These previously known occlusion balloons, however, have various drawbacks, including variability in deployment of the balloon to the desired shape, inefficiency in removing emboli, and/or high cost and complicated processes associated with manufacturing the balloon.[0004]
• In applicant's co-pending U.S. patent application Ser. No. 09/418,727, filed Oct. 15, 1999, which is incorporated herein by reference in its entirety, applicant describes the use of a bell or pear-shaped occlusion balloon disposed on the distal end of an arterial catheter. The occlusion balloon comprises a compliant material having a variable thickness along its length to provide a bell-shape when inflated. The balloon is affixed to distal end of the catheter so that a distal portion of the balloon extends beyond the distal end of the catheter to provide an atraumatic tip or bumper for the catheter.[0005]
• The balloon of that catheter may be formed using previously known techniques, such as varying the thickness of the balloon wall to achieve the preferred bell-shape in the deployed position. Such processes, however, can lead to variability in the final product due to the manufacturing process. Because variable thickness balloons present greater difficulties during manufacture than balloons having uniform wall thickness, the cost of such balloons may be higher.[0006]
• In view of the foregoing limitations of previously known devices, it would be desirable to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to enhance manufacturability of the occlusion balloon.[0007]
• It also would be desirable to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to reduce manufacturing cost and enhance product yield.[0008]
• It further would be desirable to provide an apparatus for removing emboli from a vessel comprising a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and efficiently removes emboli.[0009]
SUMMARY OF THE INVENTION
• In view of the foregoing, it is an object of this invention to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to enhance manufacturability of the occlusion balloon.[0010]
• It also is an object of the present invention to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to reduce manufacturing cost and enhance product yield.[0011]
• It further is an object of the present invention to provide an apparatus for removing emboli from a vessel comprising a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and efficiently removes emboli.[0012]
• The foregoing objects of the present invention are accomplished by providing interventional apparatus comprising a catheter having proximal and distal ends, a working lumen extending therethrough and an occlusion balloon having proximal and distal ends disposed on the distal end of the catheter. The occlusion balloon has a contracted state suitable for insertion into a vessel and a deployed state configured to occlude antegrade flow in the vessel.[0013]
• In a preferred embodiment, the catheter comprises an inner layer covered with a layer of flat stainless steel wire braid and a polymer cover. A distal section of the occlusion balloon is melt-bonded to a distalmost end of the inner layer and, optionally, to a distalmost end of the polymer cover to form a substantially seamless transition into the working lumen of the catheter. The proximal end of the occlusion balloon is everted and affixed to the polymer cover to form an inflation chamber between the polymer cover and the balloon.[0014]
• In the deployed state, the occlusion balloon is configured to extend distal of the catheter and provides a funnel-shaped transition into the working lumen of the catheter. A distal edge of the occlusion balloon is configured to be in close proximity with an inner wall of a vessel to facilitate retrograde flow into the working lumen of the catheter and efficiently remove emboli. Additionally, because the occlusion balloon of the present invention comprises a uniform thickness, the balloon may be more reliable, easier to manufacture and more cost-effective than an occlusion balloon having a variable thickness along its length.[0015]
• Preferred methods of making and using the apparatus of the present invention also are disclosed.[0016]
BRIEF DESCRIPTION OF THE DRAWINGS
• Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments, in which:[0017]
• FIGS.[0018]1A-1B are, respectively, side and sectional views of a previously known occlusion balloon in contracted and deployed states;
• FIGS.[0019]2A-2B are, respectively, a schematic view of apparatus in accordance with the present invention and a cross-sectional view along line A-A of FIG. 2A;
• FIGS.[0020]3A-3B are side sectional views illustrating a preferred configuration of the distal end of the catheter of FIG. 2;
• FIGS.[0021]4A-4B are side sectional views of the occlusion balloon of the present invention in contracted and deployed states, respectively; and
• FIG. 5 is a schematic view of apparatus of the present invention being used during an interventional procedure.[0022]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Referring to FIGS.[0023]1A-1B, a bell-shaped occlusion balloon, as described in applicant's commonly assigned allowed U.S. patent application Ser. No. 09/418,727, filed May 8, 2001, which is incorporated herein by reference, is described.Occlusion balloon20 is shown in contracted and deployed states in FIGS. 1A and 1B, respectively.Balloon20 is affixed todistal end26 ofcatheter22, for example, by gluing or a melt-bond, so that opening27 inballoon20 leads intolumen28 ofcatheter22.Balloon20 preferably is wrapped and heat treated during manufacture so thatdistal portion29 of the balloon extends beyond the distal end ofcatheter22 and provides an atraumatic tip or bumper for the catheter. In accordance with manufacturing techniques which are known in the art,occlusion balloon20 comprises a compliant material, such as polyurethane, latex or polyisoprene which has variable thickness along its length to provide a bell-shape when inflated.
• As described hereinabove, the variable thickness characteristic of[0024]occlusion balloon20, which is used to deploy the balloon to the preferred bell-shape, presents certain manufacturing challenges. In particular, manufacturing a balloon having a variable wall thickness can lead to reduced yield due to variability of the manufacturing process. Additionally, a variable thickness balloon may be difficult to manufacture and may have a higher cost relative to a balloon having a uniform thickness.
• Referring now to FIG. 2, a first embodiment of apparatus constructed in accordance with principles of the present invention is described.[0025]Apparatus40 comprisescatheter41 having proximal and distal ends and workinglumen58 extending therethrough.Catheter41 comprisesocclusion balloon42 having proximal and distal ends affixed to the distal end ofcatheter41, and preferably comprisesradiopaque marker band65 disposed at the distal end ofcatheter41 to facilitate positioning of the distal end of the catheter.
• [0026]Occlusion balloon42 comprises a uniform thickness material having a contracted state suitable for insertion into a vessel and a deployed state in whichocclusion balloon42 occludes antegrade flow in the vessel. In the deployed state,occlusion balloon42 comprisesdistal taper66 that is configured to provide a funnel-shaped transition into workinglumen58 so that blood flows in a non-turbulent fashion from a treated vessel intocatheter41. Additionally,distal edge68 is configured to be in close proximity with an inner wall of a vessel to facilitate blood flow intocatheter41 and efficiently remove emboli.
• [0027]Catheter41 preferably comprisesinner layer60 of low-friction polymeric material, such as polytetrafluoroethylene (“PTFE”), covered with a layer of flat stainlesssteel wire braid61 and polymer cover62 (e.g., polyurethane, polyethylene, or PEBAX), as shown in FIG. 2B. Workinglumen58 is defined as a lumen within an interior surface ofinner layer60.Inflation lumen63 preferably is disposed withinpolymer cover62 so that the inflation lumen does not substantially increase the overall profile ofcatheter41.
• [0028]Apparatus40 preferably further includes proximalhemostatic port43, e.g., a Touhy-Borst connector,inflation port44, andblood outlet port48.Inflation port44 is coupled toinflation lumen63, which in turn is coupled toocclusion balloon42. Proximalhemostatic port43 and workinglumen58 ofcatheter41 are sized to permit interventional devices, such as angioplasty balloon catheters, atherectomy devices and stent delivery systems to be advanced through the working lumen when a guidewire (not shown) is positioned within the working lumen.
• [0029]Blood outlet port48, which is in fluid communication with workinglumen58, may be coupled to an external aspiration device, e.g., a syringe, to cause blood flow distal ofocclusion balloon42 to flow into workinglumen58. Alternatively, in a preferred embodiment,blood outlet port48 may be coupled to a venous return catheter to form an arterial-venous shunt suitable for providing retrograde flow in a treatment vessel. This aspiration embodiment comprising an arterial-venous shunt is described in detail in applicant's commonly-assigned, above-incorporated U.S. patent application Ser. No. 09/418,727.
• Referring now to FIG. 3, a preferred configuration of[0030]catheter41 and a preferred method for affixingocclusion balloon42 to the distal end ofcatheter41 are described. In FIG. 3A, the distal end ofcatheter41 is shown from a side sectional view as comprisinginner layer60 covered with a layer of flat stainlesssteel wire braid61 andpolymer cover62.Radiopaque marker band65 preferably is disposed at the distal end ofcatheter41 betweenwire braid61 andpolymer cover62, as shown in FIG. 3A. In accordance with principles of the present invention,occlusion balloon42 comprises a uniform thickness along its length, as illustrated in FIGS.3A-3B.
• In a preferred method of manufacture,[0031]distal end50 ofocclusion balloon42 is positioned atoppolymer cover62 near the distal end ofcatheter41 and just distal of opening70 ofpolymer cover62, as shown in FIG. 3A.Distal end50 ofocclusion balloon42 then is affixed topolymer cover62, preferably using a melt-bond or, alternatively, using a biocompatible glue. At this time,proximal end52 ofocclusion balloon42 extends freely beyond the distal end ofcatheter41, as shown in FIG. 3A. For purposes of clarifying terminology used herein, althoughproximal end52 ofocclusion balloon42 appears situated distal ofdistal end50 in FIG. 3A, this is becauseproximal end52 will subsequently be everted to extend proximal ofdistal end50, as described hereinbelow.
• In a next manufacturing step,[0032]distal section51 ofocclusion balloon42, which is situated just proximal ofdistal end50, is melt-bonded to at least one polymeric layer ofcatheter41. Specifically, in a preferred embodiment,distal section51 ofocclusion balloon42 is melt-bonded todistalmost end85 ofinner layer60 and, optionally, to distalmost end87 ofpolymer cover62 to form fusion joint67, as shown in FIG. 3A. The melt-bonding of the plurality of polymeric materials at fusion joint67 provides substantiallyseamless transition72 betweenocclusion balloon42 andinner layer60. Additionally, because fusion joint67 is formed from a plurality of compliant polymeric materials, fusion joint67 is capable of achieving a flexible range of motion.
• [0033]Proximal end52 ofocclusion balloon42 then is everted so that it extends proximally and radially outward fromcatheter41, as shown in FIGS. 3B and 4A.Proximal end52 is affixed topolymer cover62, preferably using a melt-bond or, alternatively, using a biocompatible glue, at a distance between about 10-20 mm proximal of the distal end ofcatheter41, as shown in FIG. 4A. This createsinflation chamber74 betweenpolymer cover62 and an interior surface ofballoon42.Opening70, which is disposed in a lateral surface ofpolymer cover62, is in fluid communication withinflation lumen63 andinflation chamber74, as shown in FIG. 3B.Proximal end52 ofocclusion balloon42 may be stretched while it being affixed topolymer cover62 so thatapparatus40 may achieve a reduced profile in the contracted state.
• The fusion of[0034]occlusion balloon42 tocatheter41 at fusion joint67 and subsequent eversion of the balloon creates substantiallyseamless transition72 into workinglumen58, as shown in FIG. 3B. In accordance with principles of the present invention, the provision of substantiallyseamless transition72 may help reduce flow impedance into workinglumen58 and enhance flow within a treated vessel.
• Referring now to FIGS.[0035]4A-4B, deployment ofapparatus40 within vessel V of a patient is described. In FIG. 4A,occlusion balloon42 is shown in a contracted state suitable for percutaneous and transluminal insertion into a patient's vessel.Occlusion balloon42 is inflated viainflation port44,inflation lumen63 andopening70, and deploys to a predetermined configuration havingproximal taper64 anddistal taper66, as shown in FIG. 4B. The predetermined configuration may be determined, for example, using a pre-molding process in accordance with manufacturing techniques that are known in the art. In the deployed state, an outer surface ofcentral section75, which is formed between proximal anddistal tapers64 and66, is substantially flush with an inner wall of vessel V. As will be understood by those skilled in the art, the expanded diameter ofcentral section75 may be sized accordingly for different vessels.
• [0036]Distal edge68 is defined as a section ofocclusion balloon42 that is formed betweencentral section75 anddistal taper66. In the deployed state,distal edge68 is configured to be in close proximity with an inner wall of vessel V to facilitate blood flow into workinglumen58 and efficiently remove emboli.
• [0037]Distal taper66 provides a funnel-shaped flow transition fromdistal edge68 into workinglumen58. Additionally, as described hereinabove, fusion joint67 provides substantiallyseamless transition72 fromocclusion balloon42 into workinglumen58 due to the melt-bond betweenballoon42 andinner layer60 ofcatheter41.
• Referring now to FIG. 5, a preferred method for using[0038]apparatus40 of FIG. 2A during an interventional procedure, such as balloon angioplasty, is described. In a first step, guidewire83 is inserted into a patient's vasculature and a distal end ofguidewire83 is disposed just proximal of stenosis S, which is located in vessel V. A dilator (not shown) that is disposed withincatheter41 then is inserted overguidewire83 to advancecatheter41 to a desired position proximal of stenosis S. Whencatheter41 is properly positioned, e.g., as determined under fluoroscopy usingradiopaque marker band65, the dilator may be removed.Occlusion balloon42 then is inflated viainflation port44 of FIG. 2A, preferably using a radiopaque contrast solution, to occlude antegrade flow in vessel V. Aspiration is provided through workinglumen58 ofcatheter41 to cause retrograde flow to occur in vessel V distal ofocclusion balloon42, as illustrated by the arrows in FIG. 5.
• Aspiration may be provided through working[0039]lumen58 viablood outlet port48 using an external aspiration device, e.g., a syringe, or alternatively using a venous return catheter to form an arterial-venous shunt, as described hereinabove.
• An interventional instrument, such as conventional[0040]angioplasty balloon catheter80 havingballoon82, may be loaded throughhemostatic port43 and workinglumen58 and positioned within stenosis S, preferably viaguidewire83.Hemostatic port43 is closed and the angioplasty balloon is actuated to disrupt stenosis S. As seen in FIG. 5, emboli E formed during the interventional procedure are directed into workinglumen58 via the retrograde flow established.
• [0041]Occlusion balloon42 provides a substantially uniform funnel-shaped transition from an inner wall of vessel V into workinglumen58 ofcatheter41.Distal edge68, which is configured to be in close proximity with an inner wall of vessel V, facilitates flow into workinglumen58 and efficiently removes emboli. Additionally, the funnel-shaped transition provided bydistal taper66 and substantiallyseamless transition72 into the working lumen via fusion joint67 improves retrograde flow dynamics into workinglumen58.
• Advantageously, because the present invention utilizes an occlusion balloon having a uniform thickness and relies on pre-molding of the occlusion balloon to obtain the desired deployed shape, a variable thickness occlusion balloon is not required. As noted hereinabove, use of an occlusion balloon having a uniform thickness provides several advantages, including enhanced manufacture, reduced cost and increased reliability.[0042]
• While preferred illustrative embodiments of the invention are described above, it will be apparent to one skilled in the art that various changes and modifications may be made. The appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention.[0043]

Claims (20)

1. Apparatus for removing emboli from a vessel during an interventional procedure, the apparatus comprising:

a catheter having proximal and distal ends, a working lumen extending therethrough; and

an occlusion balloon having a distal end affixed to an interior surface of the working lumen and a proximal end everted to surround, and affixed to, a portion of the catheter proximal of the distal end of the catheter disposed on the distal end of the catheter, the occlusion balloon having a contracted state suitable for insertion into a vessel and a deployed state configured to occlude antegrade flow in the vessel,

wherein the occlusion balloon comprises a wall having a substantially uniform thickness along its length, and in the deployed state, provides a funnel-shaped transition into the working lumen.

2. The apparatus ofclaim 1 wherein the working lumen has an interior polymer cover.

3. The apparatus ofclaim 2 wherein the distal end of the occlusion balloon is fused to the interior polymer cover.

4. The apparatus ofclaim 3 wherein the distal end of the occlusion balloon is adhesively bonded to the interior polymer cover.

5. The apparatus ofclaim 3 wherein the occlusion balloon further comprises a distal section situated just proximal of the distal end, wherein the distal section of the occlusion balloon is fused to a distalmost end of the interior polymer cover.

6. The apparatus ofclaim 5 wherein an exterior surface of the catheter comprises an exterior polymer cover.

7. The apparatus ofclaim 5 wherein the proximal end of the occlusion balloon is fused to the exterior polymer cover.

8. The apparatus ofclaim 7 wherein the proximal end of the occlusion balloon is affixed to the exterior polymer cover at a distance between about 10-20 mm proximal of the distal end of the catheter.

9. The apparatus ofclaim 7 wherein the proximal end of the occlusion balloon is adhesively bonded to the exterior polymer cover.

10. The apparatus ofclaim 2 further comprising an inflation lumen disposed within the exterior polymer cover that is in fluid communication with the occlusion balloon.

11. The apparatus ofclaim 2 further comprising a radiopaque marker band disposed at the distal end of the catheter.

12. The apparatus ofclaim 11 wherein the catheter comprises a wire braid disposed between the interior polymer cover and the exterior polymer cover, the apparatus further comprising a radiopaque marker band disposed between the wire braid and exterior polymer cover.

13. The apparatus ofclaim 1 wherein the occlusion balloon further comprises a proximal taper in the deployed state.

14. The apparatus ofclaim 1 further comprising a blood outlet port coupled to the proximal end of the catheter.

15. A method of manufacturing an emboli catheter for use in an interventional procedure, the method comprising:

providing a catheter having an exterior surface, proximal and distal ends and a working lumen extending therethrough having an interior surface;

providing an occlusion balloon having first and second ends and a uniform thickness therebetween;

affixing a first end of the occlusion balloon to the interior surface of the working lumen;

everting the second end of the occlusion balloon over the distal end of the catheter so that the second end is disposed surrounding the catheter at a position proximal of the distal end; and

affixing the second end of the occlusion balloon to the exterior surface of the catheter at the location proximal of the distal end.

16. The method ofclaim 15 wherein the interior surface of the working lumen comprises an interior polymer cover, and affixing the first end of the occlusion balloon to the interior surface of the working lumen comprises fusing the first end to the interior polymer cover.

17. The method ofclaim 15 wherein the interior surface of the working lumen comprises an interior polymer cover, and affixing the first end of the occlusion balloon to the interior surface of the working lumen comprises adhesively bonding the first end to the interior polymer cover.

18. The method ofclaim 15 wherein the exterior surface of the catheter comprises an exterior polymer cover, and affixing the second end of the occlusion balloon to the exterior surface of the catheter comprises fusing the second end to the exterior polymer cover.

19. The method ofclaim 15 wherein the exterior surface of the catheter comprises an exterior polymer cover, and affixing the second end of the occlusion balloon to the exterior surface of the catheter comprises adhesively bonding the second end to the exterior polymer cover.

20. The method ofclaim 15 wherein providing a catheter further comprises providing a catheter having a radiopaque marker band disposed on the catheter adjacent to the distal end.

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